Patching basically is the correction or fixing of existing bugs in the software. It can be fixing of security vulnerabilities, and any corrections will be delivered by Oracle in terms of patches, and we have to apply them in Oracle home and need to execute scripts depending on the type of patch. The different types of patches are as follows:
Bug fix patches (for example, internal errors, memory- or SGA-related bugs, high CPU usage, and so on)
CPU/SPU patches
PSU patches
How to upgrade a patch set level (11.2.0.1 to 11.2.0.3)
Interim patches are also known as one-off patches. For every bug that Oracle delivers, depending on the version and release, bug fixes can be delivered as patches or they will be fixed in the next releases or versions. An interim patch is a fix only for a particular bug. Bugs differ from environment to environment depending upon the OS and Oracle version. Interim patches come in a zipped format, and you have to unzip them...